The present disclosure relates to optoelectronic integrated circuits and, more specifically, to optoelectronic integrated circuit structures with grating couplers and methods of forming those structures. Generally, optoelectronic integrated circuit chips comprise a variety of optical devices. For example, optical waveguides transmit optical signals (also referred to herein as light signals or light beams) on an optoelectronic integrated circuit chip. Photodetectors (also referred to herein as photosensors or optical receivers, such as photodiodes) receive optical signals from optical waveguides and convert the optical signals into electronic signals for processing by electronic devices on the chip. Light-emitting diodes (LEDs) or laser diodes receive electronic signals from electronic devices, convert the electronic signals into light signals and transmit the light signals to optical waveguides. Grating couplers couple optical waveguides with off-chip optical devices, such as optical fibers, so that optical signals can be received on the chip from the off-chip optical device and/or transmitted off the chip to the off-chip optical device. Silicon is often used as the core material of an optical waveguide because silicon is transparent to optical signals in the infrared wavelength bands. Silicon is often also used for the adjacent grating coupler because silicon grating coupler formation can be easily integrated with current optoelectronic integrated circuit processing. Typically, a silicon grating coupler is formed adjacent to one end of a silicon optical waveguide and on the same horizontal plane as that silicon optical waveguide. However, the alignment tolerance achievable with such a configuration is relatively small and some applications (e.g., automated wafer scale testing, automated die or module scale testing, automated packaging, etc.) require a greater alignment tolerance.